Texas Instruments has introduced several battery management integrated circuits (ICs) including its next-generation Impedance Track "gas gauge" chipset. They enable improving battery performance and protecting multicell, lithium-based battery packs used in notebook computers and other systems.
One example is TI's bq20z90 Impedance Track battery gas gauge that monitors battery capacity, impedance, cell balance, open-circuit voltage and other critical parameters of a 7.2 V, 10.8 V or 14.4 V battery pack and reports the information to the system host controller over a serial-communication bus.

TI's Impedance Track gas gauge technology, launched in 2004 with the bq20z80 chipset, precisely measures changes in impedance, or resistance caused by battery age, temperature and cycle life, to accurately predict run-time of battery packs with two, three and four cells in series. An exact "starting position" is determined for instant state-of-charge. Then total capacity is calculated from the amount of capacity that exists, which eliminates the need for a full-charge and discharge cycle.

The bq20z90 drives a three-, four- or five-segment LED display for remaining capacity indication. The device integrates SHA-1, 128-bit decryption functionality which easily identifies potentially unsafe batteries not approved by original equipment manufacturers for use in their devices. If the battery information checks out, the system will allow normal system operation with the battery pack. A manufacturer can program the system to take action to protect the consumer if the battery pack response is not correct, or if the battery pack is not approved or determined to be defective.
The bq20z90 is available in volume production from TI and its authorized distributors. The device is packaged in a 30-pin thin shrink small outline Package (TSSOP). The suggested price in 1000 piece quantities is $3.30.

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